The present invention relates to medical catheters, and more particularly to catheters used to remove substances from, or introduce substances into, the pulmonary system or gastrointestinal tract of a patient.
In certain medical treatment situations, catheters must be precisely introduced into a patient""s pulmonary system or gastrointestinal tract for various functions. For example, a patient may require involuntary aspiration of secretions from the patient""s lungs. In this situation, a suction catheter can be introduced into the patient""s airway and lungs to remove the secretions via suction through the catheter. In addition, a patient may require introduction of various substances into the body through such catheters. For example, a patient may require the introduction of a lavage solution into the lungs to loosen secretions without interfering with ventilation.
Respiratory distress frequently occurs in infants and small children, especially prematurely born infants. Premature infants may require repeated pulmonary intervention. When an infant or small child is unable to effectively breathe on their own, intubation and involuntary ventilation is provided via an endotracheal tube. In caring for infant patients, it is necessary to periodically suction out secretions that would otherwise accumulate in the infant""s lungs. This requires periodic involuntary removal of secretions from the lungs via a small suction catheter tube without injury to the lungs. Suctioning and/or introduction of therapeutic substances may take place intermittently during ventilation.
Suctioning is generally accomplished by introducing and advancing one end of a flexible suction catheter tube into the endotracheal tube and applying suction to the other end of the catheter tube. To reduce the extent of airway occlusion, the catheter tube is typically withdrawn from the endotracheal tube when the catheter is not in use.
Before the catheter tube is advanced through the endotracheal tube, the catheter tube may be xe2x80x9cexposedxe2x80x9d within the catheter assembly. However, many catheters include a flexible sleeve that covers the span of tubing between the fittings of a catheter to avoid the introduction of microbial pathogens during intubation. The sleeve encloses the catheter tube and preserves the sterility of the tube in a closed system. The sleeve remains fixed to the fittings of the catheter. The sleeve is flexible so that the catheter can be advanced by manipulating the catheter from the outside of the sleeve. Thus, the catheter may be intermittently introduced without breaking the sterile field created by the sleeve around the catheter.
Precise control over the placement of the catheter tube is also required to reduce the risk of injury during placement. The catheter must be advanced far enough to effectively reach the lungs without damaging tissue by overextension of the catheter. The use of a catheter having a protective sleeve further impacts control over the catheter during placement. As the catheter is fully advanced, the sleeve may bunch, making precise control more difficult. Thus, there is a need for a catheter having a mechanism for controlling insertion depth while preventing bunching of the protective sleeve as the catheter is inserted.
The present invention is a catheter having a tube and including mechanisms that provide precision control over insertion and retraction of the catheter tube. The catheter is particularly adapted for introduction into the pulmonary system. The catheter includes an insertion depth control mechanism that acts as a stop and provides a tactile indication to the person inserting the catheter tube that a predetermined position has been reached. The catheter also includes an anti-bunching mechanism to prevent bunching of a protective sleeve disposed around the catheter tube, thereby reducing interference from the sleeve during insertion of the catheter tube.
In one embodiment, the insertion depth control mechanism comprises an insertion control member that is adjustable positioned on the catheter tube. The insertion control member includes a releasably catch to permit adjustment of its position along the catheter tube. When placed in a predetermined position that corresponds to a predetermined insertion depth, the insertion control member acts as a stop against a connector or other form attached to the tube. When the insertion control member reaches the connector or form during insertion of the tube, it bumps against the connector or form and stops the advancement of the catheter tube at a predetermined length. This resistance provides a tactile response, or feel, to a person inserting the catheter, which indicates that the catheter tube has been inserted to the predetermined depth. The insertion control member can comprise a number of different shape.
In one embodiment, the anti-bunching mechanism comprises a sleeve spreader including an outer surface concentrically disposed around the catheter tube and adjacent a tube opening of a distal connector attached to the catheter. The sleeve spreader deflects the sleeve away from the tube opening of the distal connector and prevents it from bunching at the tube opening, thereby avoiding interference with advancement of the catheter tube.